1. Field of the Invention
The present invention relates to a scroll compressor configured to compress refrigerant in a compression chamber formed between a pair of spiral plate bodies.
2. Description of Related Art
A scroll compressor is widely used as a refrigerant compressor configured to compress refrigerant of an air-conditioning device (an air conditioner or the like), for example. Generally, the scroll compressor includes a fixed scroll fixed to a housing (a case) and a movable scroll that performs an eccentrically circular movement relative to the fixed scroll. The fixed scroll and the movable scroll each include a spiral plate body and a discoid support that supports the spiral plate body, and refrigerant is compressed in a compression chamber formed therebetween. The refrigerant thus compressed is discharged to the outside of the scroll compressor via a refrigerant path (a discharge port) that provides communication between the compression chamber and the outside of the scroll compressor.
Generally, the scroll compressor includes various refrigerant paths suitable for various purposes in addition to the above refrigerant path (the discharge port). For example, in order to improve efficiency (Coefficient of Performance (COP)) of the air-conditioning device, one conventional scroll compressor (hereinafter referred to as the “conventional compressor”) includes a refrigerant path (a so-called injection port) configured to inject, from the outside, refrigerant into refrigerant that is in a process of compression. The conventional compressor includes a check valve including a reed valve extending in a direction parallel to a rotating shaft of the compressor, as a check valve provided on the refrigerant path. Since this check valve has a small sectional area on a cut surface orthogonal to the rotating shaft as compared with a check valve including a reed valve extending in a direction “perpendicular” to the rotating shaft, it is possible to relatively easily avoid mutual interference between check valves (e.g., see Japanese Patent Application Publication No. 2009-287512 (JP 2009-287512 A)).
Hereinafter, for the sake of convenience, the check valve including the reed valve extending in the direction parallel to the rotating shaft of the compressor is referred to as a “parallel check valve,” and the check valve including the reed valve extending in the direction “perpendicular” to the rotating shaft of the compressor is referred to as a “perpendicular check valve.”
In recent years, from the viewpoint of further improving efficiency of an air-conditioning device, the number of refrigerant paths that provides communication between a compression chamber of a scroll compressor and the outside tends to increase. For example, as the aforementioned refrigerant path (the injection port) configured to inject, from the outside, refrigerant into refrigerant in a process of compression, a plurality of injection ports for a cooling operation and a plurality of injection ports for a heating operation may be provided. Further, there may be provided a refrigerant path (a so-called relief port) configured to discharge part of the refrigerant from the compression chamber in order to avoid excessive compression of the refrigerant; and a refrigerant path (a so-called reducing port) configured to discharge part of the refrigerant that is in a process of compression at the time when the air-conditioning device is operated with a low load.
Generally, the plurality of refrigerant paths is provided so as to extend through a support (both the discoid support and the housing described above) that supports the fixed scroll of the scroll compressor. Respective check valves are provided in the support so as to correspond to those refrigerant paths. Therefore, as the number of refrigerant paths increases, the number of check valves that should be provided in the support also increases. As a result, it is difficult to dispose the refrigerant paths and the check valves in the support while avoiding mutual interference between the check valves.
As described above, the conventional compressor includes a parallel check valve so as to avoid the mutual interference between the check valves. However, in a case where the parallel check valve is used, it is necessary to form a refrigerant path so that a reed valve curves (in an opening/closing manner) in a direction perpendicular to the rotating shaft of the compressor because of the structure of the parallel check valve. Therefore, in a case where the parallel check valves are used, it is possible to relatively easily avoid mutual interference between check valves, but shapes of the refrigerant paths may become complicated in comparison with a case where the perpendicular check valves are used. Further, due to the complicated shape of each refrigerant path, a pressure loss in the refrigerant path increases, which may decrease efficiency of the air-conditioning device.